Heart Rhythm Disorders (cont.)

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

Ventricular fibrillation (V-fib)

Ventricular fibrillation is technically not a rapid heart rhythm because the heart ceases to beat. In ventricular fibrillation, the ventricles do not have a coordinated electrical pattern and the ventricles, instead of beating, just jiggle, or fibrillate. Since the heart doesn't beat, blood is not circulated to the body or brain and all bodily functions stop. Without a coordinated impulse to signal the ventricle to beat, sudden cardiac death occurs.

The treatment for V-fib is defibrillation with an electrical shock. Automated external defibrillators (AEDs) in public places have helped decrease the mortality from sudden cardiac death, but prevention remains the mainstay to survive this event. Some people, such as those with a very weak heart muscle or who have a prior history of ventricular fibrillation will require an implantable defibrillator to prevent future episodes of sudden death and treat this rhythm.

This rhythm is often associated with a heart attack in which the heart muscle doesn't get enough blood supply (myocardial ischemia), becomes irritated, and causes secondary irritation of the electrical system. Aside from myocardial ischemia, other causes of ventricular fibrillation may include severe weakness of the heart muscle (cardiomyopathy), electrolyte disturbances, drug overdose, and poisoning.

Ventricular tachycardia (V-tach)

Ventricular tachycardia is another rapid heart rate that originates in the ventricle. The causes are the same as those for ventricular fibrillation, but because of the electrical conduction pattern in the heart pathways, an organized signal is provided to the ventricles, potentially allowing them to beat. This remains an emergency, since V-tach may degenerate into ventricular fibrillation.